Quantum well transistor devices formed in epitaxially grown semiconductor heterostructures, typically in III-V or silicon-germanium/germanium (SiGe/Ge) material systems, offer exceptionally high carrier mobility in the transistor channel due to low effective mass along with reduced impurity scattering due to delta doping. In addition, these devices provide exceptionally high drive current performance. Although, such devices can display high channel mobilities, forming source/drain contacts with low access resistance to the channel is quite difficult, especially in SiGe/Ge and III-V material systems.